RESUMEN
Pulping of blue agave waste, from the production of tequila, was evaluated by both chemical and biomechanical pulping processes. Two conventional and two organosolv systems were used to pulp the agave waste under a standard set of conditions. The soda-ethanol process was superior in terms of delignification and pulp properties in comparison to the soda and ethanol organosolv processes for pulping of agave waste; however, the kraft process gave the best strength properties. In general, the strength of the agave waste pulps was rather poor in comparison to wood and other agro-based pulps; however, the tear strength was relatively high. This result is typical of poorly bonded sheets and may be due to the coarseness of the agave fibers and/or loss of hemicelluloses in the steaming process for the tequila production. Fungal treatment of the agave waste with Ceriporiopsis subvermispora reduced the energy consumption for mechanical refining but gave biomechanical pulps with inferior strength properties. The blue agave chemical pulps should be suitable for blending with softwood kraft pulps for publication grade paper.
Asunto(s)
Bebidas Alcohólicas , Residuos Industriales , Papel , Plantas/químicaRESUMEN
In vitro toxicity assays were performed using Duvernoy's gland secretions from the African boomslang, Dispholidus typus, and isolated rat duodenum and frog sciatic nerve-gastrocnemius muscle preparations. The Duvernoy's gland secretions of D. typus had no apparent effect on the frog sciatic nerve-gastrocnemius muscle preparation. The secretions produced an increase in baseline tonus and an increase in the rhythmic contractile force of the rat duodenum, but had no significant effect on the frequency of contractions. Atropine sulfate (10 (-6)M) effectively antagonized the excitatory effects of the Duvernoy's gland secretions at concentrations 200 µ/ml. Although the coagulopathic effects of D. typus are well documented, this report provides preliminary data indicating effects of this venom on neuromuscular preparations.
Asunto(s)
Ratas , Técnicas In Vitro , Músculos , Nervio Ciático , Ratas , Venenos de Serpiente/farmacologíaRESUMEN
Four patients had serum sickness-like reactions during treatment with cefprozil, a new cephalosporin. Two patients had had previous mild reactions associated with cephalosporin therapy. It remains uncertain whether cefprozil-associated serum sickness-like reaction represents a unique or a class-related adverse drug reaction.
Asunto(s)
Cefalosporinas/efectos adversos , Enfermedad del Suero/inducido químicamente , Adulto , Bronquitis/tratamiento farmacológico , Niño , Preescolar , Femenino , Humanos , Masculino , Otitis Media/tratamiento farmacológico , Sinusitis/tratamiento farmacológico , CefprozilRESUMEN
To obtain additional data concerning uranium mining and nonmalignant respiratory diseases, we conducted a prevalence survey of 192 long-term New Mexico uranium miners. Survey procedures included spirometry, completion of a respiratory symptoms questionnaire, physical examination and interpretation of available chest x rays. Total duration of underground uranium mining was used as the exposure index. Of the major respiratory symptoms, only the prevalence of dyspnea increased significantly with duration of uranium mining. With linear multiple-regression analysis, small but statistically significant effects of mining were found for two spirometric parameters, the forced expiratory volume in one sec and the maximal midexpiratory flow. By the 1980 International Labor Organization (ILO) U/C classification, 12 of 143 participants with x rays available for interpretation had at least category 1/0 pneumoconiosis. The opacities were predominantly nodular and compatible with silicosis.